Rated 3 times stronger than stock our upgraded driveline consists of larger U-joints, yokes, larger diameter shafts with double the wall thickness 0than the stock/OEM drivelines from Polaris. When you operate your RZR over 40 MPH you are exceeding what the driveline is rated for, our driveline was engineered for your machines capabilities & much much more. Make sure to check out our GEN3 carrier bearing it is needed with our upgraded driveline & corrects the driveline angle so it is a must have! (GEN3 CARRIER BEARING NOT INCLUDED)